PL A I I : \ \M ' 



LEPTODESMA I'MI'.oN \-itm. \:ii\ DEFRES80M. 



I _. ii. The 8] in lied, knot] a is.given on plate 90, fig. 10. 



Chei i >• 



Leptodesma NAVIFORME. 



23. 

 Fig. 15. The left valve described. The rid las more extended and acute, 



and the extremitj of tin 



Chemung | . 1*. 



LePTODESM \ POTENS, V&V. II PENS. 



16. A left valve. 



i In mung group. T. 



LeIOPTEIU \ < ' 1 1 ! : M I NGEJ 



m. 

 Figs. 17. 18. Opposite views of the original spi jht valves. The right valve is 



lompression 

 urface of th led from the same cause. 



i'h. ip. Etyhi ■ A", r. 



Leptodesma Li sander. 



Page 216. 



■ 90. 

 Fig. 22. A left valve. The figure is partial! j restored nnd should represent theJ)odj asci usideral 

 Chei 



Leptodesma km km m i m. 



23. Aii imperfect left v alve. Am. tin r figure i, fig. 17. 



Chemung group. ' ' •■ . X. V. 



PtEBOJSI rES ttOSTRATl S. 



Fig. 24. The Left valve .1 



Chen ■■ . 1". 



PTERONITES' l'i;t >l i • n 



Fig 25. A small left valve. 



Chemung group. A ... .V. )'. 



Fig. 26. A larger example. The at) coin uti 



Cliemung group. Co., X. )". 



Fig. _7. A large individual imperf 



Chei 1'. 



LePTODESJI 1 ILIFORME. 



91. 



i . 28. A i ,hi valve. This J represents re clgarlj the 



specific charai I 



( !hemung gi p. A 



